This is an unscientific observation, however, the great blue heron (Ardea herodias) colony at Baum Lake (Lassen County CA) appears to have grown over the last ten years. Originally there were nests in two ponderosa pines and last year I counted nests in at least eight trees.
It is early in the season, yet there do not seem to be as many great blue herons this year. Great blue herons are resident in our area so perhaps more will begin to nest as spring progresses. Has the colony decreased in number or am I a little to early? Some pairs already have claimed their nest sites, as can be seen in the photograph.
Great blue herons often sit atop a snag near their nest watching over the area. In the photo specialized chest feathers add to the heron’s stately appearance. These feathers continually grow. The great blue heron rakes this feather fringe with claws on its middle toes. The raking creates a feather powder that the heron uses to remove fish oils, slime and detritus (fish are a major prey) from feathers as it preens. Powder on the heron’s underparts also protect it from scum in swampy areas.
I look forward to watching the great blue herons of Baum Lake throughout the 2016 breeding season.